\begin{tikzpicture}
    \tkzDefPoints{0/0/B, 2.6/0/C, 1.3/3/A}

    \tkzDrawPolygon(A,B,C)
    \tkzMarkSegments[mark=||](A,B  A,C)
    \tkzLabelPoints[above](A)
    \tkzLabelPoints[below](B,C)
\end{tikzpicture}

